remove optional" for detection efficiency/alive-time components

[KrisThielemans]

We have

PETSIRD/model/DetectionEfficiencies.yml

Lines 78 to 84 in fa2f043

	detectionBinEfficiencies: DetectionBinEfficiencies*?
	# Nested list of lookup tables for SGIDs, one for each module-type pair.
	# Also indicates if coincidences between a module-pair are recorded.
	modulePairSGIDLUT: ModulePairSGIDLUT**?
	# Nested list of all modulePairEfficienciesVectors (one for each module-type pair)
	# Constraint: size(modulePairEfficienciesVectors[type_of_module1][type_of_module2]) == max(modulePairSGIDLUT[type_of_module1][type_of_module2]) + 1
	modulePairEfficienciesVectors: ModulePairEfficienciesVector**?

However, for other vectors, we decided to remove the "optional" (i.e. ?) as that can be represented by a vector of length 0

Same for

PETSIRD/model/DetectionEfficiencies.yml

Line 115 in fa2f043

moduleCoincidenceAliveTimeFractions: ModuleCoincidenceAliveTimeFractions**?

(Unfortunately, "optional" was added in v0.8)